Typo fixes

doc/extending/ctype.txt

@@ -486,12 +486,11 @@ Output Guard
 ============
 
 We have an internal Op called OutputGuard. It is used for some
-verification of inplace/view Op. It have a c implementation that
-increment/decrement Python reference counts. If your type represent an
-Python object, OutputGuard c code should work with your type. You must
-tell OutputGuard to generate c code when working with your
-type. Otherwise, it will use python code. You tell him by executing
-this:
+verification of inplace/view Ops. It has a C implementation that
+increments/decrements Python reference counts. If your type represents a
+Python object, OutputGuard C code should work with your type. You must
+tell OutputGuard to generate C code when working with your
+type, as otherwise it will use Python code. You can achieve this with:
 
 .. code-block:: python